c_concat.sh

#!/bin/bash
#output a run.sh that real cut and concat the file
#use ffmpeg,thanks for its developer
if [ "$1" = "" ] || [ "$2" = "" ] || [ "$3" = "" ]
then
	echo "please input paramenter:\$1[time_pairs_txt],\$2[media_file],\$3[media_file]"
	exit 2
fi

time_pairs_txt=$1 #txt file that contain time suits for trim
input=$2
#input=${input//' '/'\ '}
input=`printf %q "$input"`
output='date "+%Y_%m_%d_%H_%M_%S"'
dir_name=.cut_video
dir_path=$3
sh_dir=$4
IFS=$'/' f=($2)
file_name=${f[${#f[*]}-1]}
#file_name=${file_name//' '/'\ '}
echo "file name:$file_name"
IFS=$'.' t=($file_name)
file_format=${t[${#t[*]}-1]}
# cat $time_pairs_txt | while read line
# do
# 	 IFS=',' seg=($line)
# 	 left=${seg[0]}
# 	 right=${seg[1]}
# 	 echo "left:$left,right:$right"
# done
echo "dirpath:$dir_path"
eval cd "$sh_dir"
echo "path:$dir_path"
echo "f:`pwd`"
echo "cd \"$dir_path\"" > run.sh
echo "mkdir $dir_name" >> run.sh


IFS=$'\n' a=(`eval cat $time_pairs_txt`)
num=${#a[@]}
for  i  in  ${!a[@]};do
	IFS=',' seg=(${a[i]})
	left=${seg[0]}
	right=${seg[1]}
	duration=$(echo "scale=2;$right-$left" |bc)
	# echo "[$i]left:$left,right:$right"
	#gen a new run.sh
	# if [ $i = 0 ]
	# then
	# 	echo "echo \"file 'clip$i.mkv'\" >>$dir_name/concat.txt" >run.sh
	# fi
	echo "ffmpeg -ss $left -i $input -t $duration -c  copy -avoid_negative_ts 1 $dir_name/clip$i.$file_format" >>run.sh
	#-avoid_negative_ts avoid ffmpeg starting from negative time.
	#echo "ffmpeg -y -accurate_seek -ss $left  -t $duration -i '$input' -c  copy -avoid_negative_ts 1 $dir_name/clip$i.$file_format" >>run.sh
	#When transcoding and -accurate_seek is default enabled ,this make accurate time cut ,but when doing stream copy it won't work.
	echo "echo \"file 'clip$i.$file_format'\" >>$dir_name/concat.txt" >>run.sh

done

# if 

# if [ $num == 1 ]
# then
#    echo "cp mode"
#    #echo "cp clip0.mkv ../"\`$output\`"_cat_$file_name" >>run.sh
# else
#    echo "concat mode"
#    #echo "ffmpeg -f concat -i $dir_name/concat.txt -c copy "\`$output\`"_cat_$file_name" >>run.sh
# fi
if [ $num == 1 ]
then
   echo "cp mode"
   echo "cp $dir_name/clip0.$file_format \"\`$output\`_cut_$file_name\"" >>run.sh
else
   echo "concat mode"
   echo "ffmpeg -f concat -i $dir_name/concat.txt -c copy \"\`$output\`_cut_$file_name\"" >>run.sh
fi

echo "rm -rf $dir_name" >>run.sh
echo "echo OK!" >>run.sh
echo "echo srcipt_dir:`pwd`" >>run.sh
chmod +x run.sh
echo "run.sh has generated"